Although not limited in this respect, radio Frequency Identification (RFID) may refer to technologies that may use radio waves to identify objects. RFID systems may provide non-contact, non-line-of-sight identification. RFID systems may utilize three components, an antenna or coil, a transceiver (with decoder), and a transponder (RF tag) electronically programmed with unique information. However, it is understood that RFID systems may have more or less components based on the use requirements and the present invention is not limited to the RFID system comprising these components.
The antenna may send out radio signals that activate the tag's electronics allowing data to be read and possibly written to the tag's electronically erasable programmable read-only memory (EEPROM). The antenna may be packaged with the transceiver and decoder to become an interrogator, typically called a reader even though it may write to writeable tags as well, although the present invention Is not limited in this respect. RFID tags may be read-only or read/write and may be read or written to through a variety of substances where barcodes or other optically read technologies would be useless. RFID tags may be categorized as either active or passive where passive tags may obtain power from the reader and operate without a separate external power source while an internal battery powers active tags.
Current RFID tags cannot report their local power detected but rather the RFID reader has to rely solely on the tag reflected power for any kind of power control. Further, current tags have no provisions for reporting their individual power level other than an absolute cut-off when there is not enough power to power the tag
Thus, a strong need exists for radio frequency identification tags capable of reporting receiver signal strength indications and for methods of operation therefore.
It will be appreciated that for simplicity and clarity of illustration, elements illustrated in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements are exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals have been repeated among the figures to indicate corresponding or analogous elements.